Left ventricular global strain and duration of QRS complex as predictors of prognosis after cardiac resynchronization therapy

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Public Institution(s). Main funding source(s): National heart institute and Menoufia university, Egypt. BACKGROUND: cardiac resynchronization therapy is effective for patients with chronic heart failure with reduced left ventricular ejection fraction and wide QRS (≥120 ms). We aimed to verify that a baseline left ventricular global longitudinal strain(LVGLS) and qrs duration may be beneficial as predictors of prognosis of CRT response. PURPOSE: We aimed to evaluate if LVGLS & QRS duration may be of additive prognostic value in CRT response. METHODS: Transthoracic echocardiography was performed prior to and 6 months after CRT implantation. Echocardiography was performed to assess left ventricular function as LVGLS. The response to CRT was defined as improvement in NYHA functional class (at least one class) and ≥ 15% reduction in the left ventricular end-systolic volume or improvement in left ventricular ejection fraction > 10. Comparison between responders and not responders was done using the appropriate test, and ROC analyses were done for QRS duration and LVGLS to predict CRT response. RESULTS: fifty-five HF patients (age 58 ±8 years, LVEF 23 ±5%, QRS duration 159 ±8ms, 30.9% ischemic aetiology of HF) underwent CRT implantation. The percentage of responders was 72.72% (Table). Baseline LVGLS differed significantly according to CRT response (P < 0.019). The best cutoff for LVGLS to predict response was 6.2, at which sensitivity and specificity were 70% and 73.3%, respectively with AUC of 0.793, with a 95% confidence interval (CI) of 0.651 - 0.936 (P = 0.001). Also, there was a statistically significant difference of the baseline QRS duration between the patients who had and hadn’t CRT response (P <0.001). The best cutoff was >154 ms,at which sensitivity and specificity were 87.5% and 86.7%, respectively. (AUC was of 0.793, with a 95% CI ranging from 0.651 - 0.936 (P = 0.001). CONCLUSION: Baseline LVGLS and QRS duration may have a prognostic value in prediction CRT response. Baseline LVGLS (>6.2) and QRS duration (>154ms) may help to select CRT responders. [Figure: see text] [Figure: see text]